The invention relates to an aqueous composition for treating hair, especially to a hair fixing composition, which contains a thickener and a fixing or film-forming polymer which can be precipitated completely or partially in aqueous solution by changing the pH value, has a pH value at which it is precipitated completely or partially and is soluble at other pH values.
Conventional hair treatment compositions containing natural, synthetic or modified natural film-forming polymers generally take the form of alcoholic preparations, aqueous-alcoholic preparations or preparations containing some other organic solvent.
When used daily, organic solvents in hair grooming products have a negative effect on humans and on the environment. They also have an unpleasant odor. If the organic solvent contained in such compositions is replaced by water, this usually leads to a deterioration of its useful properties, e.g., results in slow drying of hair. In such cases, the hair usually feels sticky.
Hair fixing compositions with an intensive setting or fixing action contain high proportions of one or more film-forming fixing polymers so that the use of such compositions greatly burdens the hair, particularly fine hair. Moreover, hair can become sticky.
Currently conventional forms for such compositions are sprays, lotions, foams and gels. The problems mentioned above frequently occur with gels in particular.
Further, hair treatment compositions in gel form have limited fixing or holding power.
European Patent Application EP-OS 0 445 714 describes hair fixing compositions containing sodium alginate, a fixing polymer and water as solvent. However, the fixing power of such compositions is limited. Furthermore, they can burden hair.
European Patent Application EP-OS 0 412 705 discloses a cosmetic hair composition which contains a nonionic, water-soluble thickening polymer which is modified with respect to hydrophobic properties, a second water-soluble thickening polymer and a hair-fixing polymer which is soluble or insoluble in water. Special silicone copolymers which are dissolved in liquid silicone derivatives are worked into the composition as preferred fixing polymers. Due to the use of silicon-organic solvents, such compositions are not sufficiently environmentally friendly.
A hair care composition with holding properties containing a water-insoluble polymeric complex is described in European Patent Application EP 0 034 190 A1. The insoluble polymeric complex is a reaction product of an anionic polymer and a cationic surfactant. This reaction product imparts body and stiffness to the hair (page 1, lines 20 to 32). However, the hair fixing power of such compositions is limited and the requirement of the complex forming cationic surfactant substantially increases the production costs.